The Siren Board

pyramid head wrote:I do not know where I read this, but I think somebody said that STL-10's were made for mountainous area's, and the low tone is for penetration. Is this correct?

Yes, they are. According to the older Federal Signal catalogs from the 1970s, they say that the STL-10 has better penetration in hilly and mountainous areas. Also, to distinguish between other high-pitch sirens that might be in the same area.

okay, we have a 14 page revival! I am curious of the motor styles on the STL's. I notice some are just smooth and round, and others look capped and have lines going to the motor base (such as the one below).

Then the round one is like this

I would like to know what years the "capped" one was used, because it has a lot more character.